Radon mitigation with pressure-controlled mechanical ventilation

• Published in: Building and environment Vol. 29; no. 3; pp. 387 - 392
• Main Authors: Kokotti, Helmi, Keskikuru, Timo, Kalliokoski, Pentti
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.1994
• ISSN: 0360-1323; 1873-684X
• DOI: 10.1016/0360-1323(94)90039-6

Effective ventilation and positive or low negative pressure indoors are suggested to achieve low indoor radon levels. The aim of this study was to develop and to test equioment which makes it possible to achieve simultaneously effective ventilation and minimum indoor-outdoor pressure difference. The unit included mechanical supply and exhaust air fans, a heat-exchabger and a pressure control unit in direct digital control (DDC), which continuously adjusted air flows based on the pressure difference transmitter information. Indoor radon level decreased from 501±95 Bq/m 3 to 202±54 Bq/m 3 after two weeks of the equipment's installation during winter conditions. The arithmetic week average of indoor radon level was 135 Bq/m 3 from May to August. When the set value of pressure difference adjustment was slightly positive ( 0.2 Pa) and in-out temperature difference was small in August, the minimum level ( 38±28 Bq/m 3 ) was obtained.